Table 2. Diagnostic performance of percentage signal recovery (PSR) thresholds for identifying primary central nervous system lymphoma (PCNSL).

This table shows the sensitivity, specificity, positive likelihood ratio (LR+), and negative likelihood ratio (LR-) for various PSR cutoff points used to differentiate PCNSL from other CNS lesions.

LR+ and LR- were calculated as follows: LR+ = Sensitivity / (1 - Specificity) LR- = (1 - Sensitivity) / Specificity

An LR+ greater than 10 is considered strong evidence to rule in the diagnosis, while an LR- less than 0.1 supports ruling it out, aiding clinical decision-making.

Infinite (∞) values occur when specificity is 100%, indicating perfect rule-in ability at that cutoff.

The asterisk (*) and bold font indicate the optimal cutoff point (>112) selected based on the best balance between sensitivity and specificity.

PSR criterion	Sensitivity (%)	Specificity (%)	LR+	LR–
≥57	100.00	0.00	∞	0.00
>89	100.00	10.46	1.12	0.00
>90	99.12	17.27	1.20	0.05
>94	99.12	20.68	1.25	0.05
>95	96.49	21.41	1.23	0.16
>96	96.49	31.14	1.40	0.11
>97	95.61	32.12	1.41	0.14
>98	94.74	87.10	7.27	0.06
>103	94.74	98.54	63.81	0.05
>105	93.86	99.27	126.42	0.06
>108	93.86	99.27	126.42	0.06
>112 *	93.86	99.51	192.35	0.06
>115	86.84	100.00	∞	0.13
>320	0.00	100.00	0.00	1.00